Hydration backpack



FIG. 1 is a front elevational view of the present invention;

FIG. 2 is a left side view of the present invention;

FIG. 3 is an upper edge view of the present invention; and,

FIG. 4 is a lower edge view of the present invention.

The broken line(s) form no part of the claimed design.

The ornamental design for a hydration backpack, as shown and described.